Desert Storm Syndrome (DSS) is a complex collection of symptoms ranging from severe fatigue to cognitive impairment. The goal of our study is: 1) To judge the efficacy of a possible treatment for Desert Storm patients (a trial of intravenous antibiotic) and 2) To further characterize the neurocognitive correlates of DSS. The efficacy of the antibotic treatment will be determined by measures of fatigue and cognitive processing speed. The primary outcome measures for fatigue are 1) Modified Fatigue Impact Scale (MFIS-5); 2) Fatigue Assessment Inventory (FAI). These self-report questionnaires quantify both mental and physical aspects of fatigue. Cognitive processing speed will be measured using the 1) WAIS-R Digit Span, 2) the paced Auditory Serial Addition test (PASAT), and 3) the computerized Alphabet-Arithmetic (A-A) test. These three tests provide comprehensive measurements of attention. inasmuch, the A-A Test will also assess both speed of cognitive processing and reaction time. Additional measures are included to assess sleep patterns, sensations and pain, psychopathology and copying styles, and other aspects of neuropsychological functioning. Neuropsychological functioning will be measured by an estimate of general intelligence (short-form WAIS-R and WRAT-2 reading level). Learning and memory measures include the Selective Reminding Test (SRT), and WMS-R Logical memory Test, and the Continuous Visual Memory test (CVMT).